Method and apparatus for transmitting remaining minimum system information in multibeam-based system

ABSTRACT

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). The present disclosure includes an operation method of a terminal in a wireless communication system, the method including checking information on at least one control resource set carrying scheduling information for scheduling remaining system information based on a master information block (MIB) received from a base station, checking the scheduling information in the at least one control resource set, and receiving the remaining system information based on the scheduling information.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

This application is based on and claims priority under 35 U.S.C. § 119to Korean Patent Application No. 10-2017-0056831 filed on May 4, 2017and to Korean Patent Application No. 10-2017-0114152 filed on Sep. 6,2017 in the Korean Intellectual Property Office, the disclosures ofwhich are incorporated herein by reference in their entireties.

BACKGROUND 1. Field

The present disclosure relates to operations of a base station and aterminal for transmitting remaining minimum system information (RMSI),which constitutes minimum system information in a multibeam-basedsystem.

2. Description of Related Art

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a ‘Beyond 4G Network’ or a‘Post LTE System’.

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission distance, the beamforming, massive multiple-inputmultiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques are discussed in5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud RadioAccess Networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul, moving network, cooperativecommunication, Coordinated Multi-Points (CoMP), reception-endinterference cancellation and the like.

In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and slidingwindow superposition coding (SWSC) as an advanced coding modulation(ACM), and filter bank multi carrier (FBMC), non-orthogonal multipleaccess (NOMA), and sparse code multiple access (SCMA) as an advancedaccess technology have been developed.

Meanwhile, the essential information for performing a random access in a5G system may be defined as minimum system information (SI). The minimumsystem information may consist of master information block (MIB) andremaining minimum system information (RMSI), and there is a need of amethod for transmitting the RMSI.

SUMMARY

The present disclosure has been conceived to solve the above problem andaims to provide operations of a base station and a terminal fortransmitting the RMSI in a multibeam-based system. Also, the presentdisclosure aims to provide operations of a base station and a terminalfor transmitting RMSI transmission channel (RMSI being transmitted inphysical downlink shared channel (PDSCH) scheduling information via theMIB and downlink control channel information (DCI).

In accordance with an aspect of the present disclosure, a method of aterminal in a wireless communication system is provided. The methodincludes checking information on at least one control resource setcarrying scheduling information for scheduling remaining systeminformation based on a master information block (MIB) received from abase station, checking the scheduling information in the at least onecontrol resource set, and receiving the remaining system informationbased on the scheduling information.

In accordance with another aspect of the present disclosure, a method ofa base station in a wireless communication system is provided. Themethod includes transmitting a master information block (MIB) includinginformation on at least one control resource set carrying schedulinginformation for scheduling remaining system information, transmittingthe scheduling information in the at least one control resource set, andtransmitting the remaining system information based on the schedulinginformation.

In accordance with another aspect of the present disclosure, a terminalin a wireless communication system is provided. The terminal includes atransceiver configured to transmit and receive signals and a controllerconfigured to control to check information on at least one controlresource set carrying scheduling information for scheduling remainingsystem information based on a master information block received from abase station, checking the scheduling information in the at least onecontrol resource set, and receiving the remaining system informationbased on the scheduling information.

In accordance with still another aspect of the present disclosure, abase station in a wireless communication system is provided. The basestation includes a transceiver configured to transmit and receivesignals and a controller configured to control to transmit a masterinformation block (MIB) including information on at least one controlresource set carrying scheduling information for scheduling remainingsystem information, transmit the scheduling information in the at leastone control resource set, and transmit the remaining system informationbased on the scheduling information.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document: the terms “include” and “comprise,” aswell as derivatives thereof, mean inclusion without limitation; the term“or,” is inclusive, meaning and/or; the phrases “associated with” and“associated therewith,” as well as derivatives thereof, may mean toinclude, be included within, interconnect with, contain, be containedwithin, connect to or with, couple to or with, be communicable with,cooperate with, interleave, juxtapose, be proximate to, be bound to orwith, have, have a property of, or the like; and the term “controller”means any device, system or part thereof that controls at least oneoperation, such a device may be implemented in hardware, firmware orsoftware, or some combination of at least two of the same. It should benoted that the functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for certain words and phrases are provided throughout thispatent document. Those of ordinary skill in the art should understandthat in many, if not most instances, such definitions apply to prior, aswell as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 is a diagram illustrating a resource configuration for explainingan overall operation of a terminal for receiving RMSI according to anembodiment of the present disclosure;

FIG. 2 is a diagram illustrating a configuration of mini-slots accordingto an embodiment of the present disclosure;

FIG. 3 is a diagram illustrating a configuration of mini-slots accordingto another embodiment of the present disclosure;

FIG. 4 is a diagram illustrating a configuration of mini-slots accordingto another embodiment of the present disclosure;

FIG. 5 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure;

FIG. 6 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure;

FIG. 7 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure;

FIG. 8 is a diagram illustrating a resource configuration fortransmitting SS burst sets, RMSI-related CORESETs, and PDSCH accordingto an embodiment of the present disclosure;

FIG. 9 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure;

FIG. 10 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure;

FIG. 11 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure;

FIG. 12 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure;

FIG. 13 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure;

FIG. 14 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure;

FIG. 15 is a diagram illustrating a configuration of an SS burst set,RMSI-related CORESET, and PDSCH according to an embodiment of thepresent disclosure;

FIG. 16 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure;

FIG. 17 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure;

FIG. 18 is a diagram illustrating a resource configuration fortransmitting SS burst sets, RMSI-related CORESETs, and PDSCH accordingto an embodiment of the present disclosure;

FIG. 19 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure;

FIG. 20 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure;

FIG. 21 is a diagram illustrating a configuration of mini-slotsconsisting of 2 OFDM symbols each;

FIG. 22 is a diagram illustrating a method for designing referencesignals mapped to two OFDM symbols in the frequency domain according toan embodiment of the present disclosure;

FIG. 23 is a diagram illustrating a method for designing referencesignals mapped to two OFDM symbols in the time domain;

FIG. 24 is a diagram illustrating a table with OCC mapping per antennaport;

FIG. 25 is a diagram illustrating a design of TRSfrequency-division-multiplexed (FDMed) with RMSI-related PDCCH and/orPDSCH for TRS-based channel estimation according to an embodiment of thepresent disclosure;

FIG. 26 is a diagram illustrating a design of BRS for channel estimationbased on TRS FDMed with RMSI-related PDCCH and/or PDSCH according to anumber of antenna ports;

FIG. 27 is a diagram illustrating design of TRS TDMed with RMSI-relatedPDCCH and/or PDSCH for TRS-based channel estimation according to anembodiment of the present disclosure;

FIG. 28 is a block diagram illustrating a configuration of a terminalaccording to an embodiment of the present disclosure; and

FIG. 29 is a block diagram illustrating a configuration of a basestation according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 29, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

Various embodiments of the present disclosure are described in detailwith reference to the accompanying drawings. Detailed descriptions ofwell-known functions and structures incorporated herein may be omittedto avoid obscuring the subject matter of the present disclosure.Further, the following terms are defined in consideration of thefunctionality in the present disclosure, and they may vary according tothe intention of a user or an operator, usage, etc. Therefore, thedefinition should be made on the basis of the overall content of thepresent specification.

Advantages and features of the present disclosure and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of embodiments and the accompanyingdrawings. The present disclosure may, however, be embodied in manydifferent forms and should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe concept of the disclosure to those skilled in the art, and thepresent disclosure will be defined by the appended claims. Likereference numerals refer to like elements throughout the specification.

In a new radio access technology (new RAT) system (NR system), thesystem information (SI) broadcast to terminals may be divided intominimum system information (minimum SI) and other system information(other SI). The minimum SI that is minimally required for a terminal toperform random access (RA) is delivered to all users or terminals withina cell. The minimum SI is broadcast to all terminals. The other systemSI includes information excepting the minimum system information.

The minimum SI may consist of the information included in the MIB andRMSI.

The MIB is transmitted on a new radio-physical broadcast channel(hereinafter, referred to as NR-PBCH or just PBCH), and the RMSI istransmitted on a new radio-physical downlink shared channel(hereinafter, referred to as NR-PDSCH or just PDSCH). The schedulinginformation for scheduling the PDSCH carrying the RMSI may betransmitted via the MIB and DCI, and the information on the newradio-physical downlink control channel (hereinafter, referred to asNR-PDCCH or just PDCCH) carrying the DCI is transmitted via the MIB. Inthe present disclosure, it is assumed that the minimum SI is transmittedin a multibeam sweeping scheme in order for the minimum SI to bedelivered to all users within a cell.

There is therefore a need of a method for transmitting the informationon the PDCCH carrying the DCI via the MIB and a method for transmittingthe scheduling information for the PDSCH carrying the RMSI via the DCI.

FIG. 1 is a diagram illustrating a resource configuration for explainingan overall operation of a terminal for receiving RMSI according to anembodiment of the present disclosure.

As shown in FIG. 1, the terminal may acquire time-frequency resourceposition information of a control resource set (CORESET) for receiving acontrol information scheduling RMSI Tx PDSCH (hereinafter, referred toas RMSI-related CORESET) via a PBCH in synchronization signal (SS)blocks 110, 111, and 112. Here, the SS blocks may be configured toinclude resources for transmitting synchronization signals and a PBCHfor transmitting the MIB. The CORESET denotes a resource region for aterminal to search for in order to acquire control information, and theterminal can decode the DCI by searching the CORESET.

In this way, the terminal can acquire information on the RMSI-relatedCORESET, search the RMSI-related CORESET to acquire control informationfor RMSI Tx PDSCH scheduling, and decode the RMSI Tx PDSCH based on thecontrol information.

Here, the RMSI-related CORESET may be configured to transmit the DCI forscheduling the RMSI Tx PDSCH only or along with DCIs for other purposes.

The SS blocks may carry a primary synchronization signal (PSS), ansecondary synchronization signal (SSS), a PBCH, and a demodulationreference signal (DMRS) for decoding the PBCH. It is assumed that thesecond SS block 111 among M SS blocks indicates the CORESET mapped tothe second one of total N RMSI-related CORESET positions. The terminalmay receive the second CORESET 121 among the total N RMSI-relatedCORESETs using the same terminal beam as that used for receiving thesecond SS block 111 among the M SS blocks. That is, as shown in FIG. 1,the terminal may use the same terminal beam for receiving a specific SSblock and the CORESET (or RMSI) indicated in the specific SS block,under the assumption that the base station uses the same transmissionbeam to transmit a specific CORESET (or RMSI) indicated in the specificSS Block.

The RMSI-related CORESET and PDSCH may be multiplexed in the same manneras shown in FIG. 1 or in a different manner. The subcarrier spacing(SCS) for transmitting the SS blocks may be identical with or differentfrom the SCS for transmitting the RMSI-related CORESET and/or PDSCH, andthe SCS for transmitting the RMSI-related CORESET and the SCS fortransmitting the RMSI Tx PDSCH may be identical with or different fromeach other.

[RMSI Scheduling]

The aforementioned MIB being transmitted through the PBCH may includeinformation on the RMSI-related CORESET(s). The PBCH may includeinformation on the PDSCH carrying the RMSI in part as well as theinformation on the RMSI-related CORESET(s).

There may be 1) an RMSI-related CORESET having its resource position(e.g., search space) which the terminal has to perform decoding todetermine in a CORESET based on the received SS blocks or 2)RMSI-related CORESETs existing independently which the terminal has toperform decoding based on the received SS blocks. For the case of theindependently existing CORESETs which the terminal has to performdecoding, a set of RMSI-related CORESETs is configured.

For example, a CORESET may comprises multiple OFDM symbols (e.g., 30OFDM symbols), and the base station may transmit RMSI schedulinginformation through beam sweeping in one CORESET. Accordingly, theterminal may perform decoding at specific resource positions within aCORESET based on the SS blocks to acquire control information, and theresource positions for which the terminal searches to decode the controlinformation may be referred to as search space in a CORESET.

In the case where multiple CORESETs on which the terminal has to performblind decoding exist independently, the terminal may locate thepositions of the CORESETs on which the terminal has to perform decodingbased on the SS blocks and then perform decoding thereon.

As described above, it may be possible to configure one or moreRMSI-related CORESETs. The configuration information for theRMSI-related CORESET in the MIB may include at least part of theinformation listed as follows, and some information may be predefined inthe standard.

1) Subcarrier spacing or numerology of RMSI-related CORESET (s) andcyclic prefix (CP) length (normal CP or extended CP)

-   -   A base station may transmit a terminal subcarrier spacing of        RMSI-related CORESET(s) or numerology, subcarrier spacing or        numerology of an RMSI Tx PDSCH, and CP length. The subcarrier        spacing of the RMSI-related CORESET(s) and the subcarrier        spacing of the RMSI Tx PDSCH may be identical with each other        and, in this case, the MIB may indicate just one subcarrier        spacing.    -   Or, the base station may not include the above information in        the MIB and, in this case, it may be specified that the        subcarrier spacing of the RMSI Tx PDSCH and/or the CP length are        identical with each other in the standard. In the present        disclosure, the expression “transmitting a channel such as PBCH”        may mean transmitting information through the channel.

2) DCI aggregation level (AL)

-   -   Similar to that in an LTE system, the RMSI scheduling        information (DCI) being carried in the RMSI-related CORESET may        be transmitted using one or more control channel elements        (CCEs), and the base station may send the terminal an        aggregation level indicating the number of aggregated CCEs.

3) Band

A band may be expressed with a number of physical resource blocks(PRBs). This information may be band information for RMSI-relatedCORESET(s) or band information for RMSI-related CORESET(s) and a PDSCH.The band may be composed of non-consecutive PRBs.

Meanwhile, the band information may include an indicator indicating astart position, a middle position, or an end position of multiple PRBsallocated in association with the frequency position information to bedescribed later.

4) Frequency position information of RMSI-related CORESET(s)

-   -   The MIB may include frequency domain information associated the        positions of RMSI-related CORESET(s). The MIB may also include        information on the positions of DCI for scheduling RMSI in the        CORESET(s). Here, the RMSI-related DCI information may be        transmitted with or without other DCI information in the        CORESET(s).

Meanwhile, the frequency domain information of the CORESET(s) mayinclude the positions of the CORESET(s) in a minimum carrier bandwidth(BW) or the positions of the CORESET(s) in a PBCH BW. In the case wherethe system BW information is transmitted in the MIB, the system BWinformation may include the positions of the CORESET(s).

-   -   If the frequency domain information of the CORESET(s) is        provided as positions in the minimum carrier BW or PBCH BW, the        base station may send the terminal the frequency domain        information of the CORESET(s) as follows.

Alt 1. The base station may send the terminal the frequency domaininformation using the offset between the center frequency of theCORESET(s) and the center frequency of the terminal-received SSblock(s).

Alt 2. The base station may notify the terminal of the frequency domaininformation using the information of the offset between the starting orending point of the CORESET(s) in the frequency domain and the centerfrequency of the SS block(s).

Alt. 3. The base station may send the terminal the frequency domaininformation of the CORESET(s) using the information on the positions ofCORESET(s) in the minimum carrier BW or PBCH BW (e.g., starting RBnumber or RB number associated with the center frequency of theCORESET(s). Here, the CORESET position information may be an offsetvalue or RB information as described above or a value selected among afew candidate values designated in the standard.

-   -   If the frequency domain information of the CORESET(s) is        provided in the form of the positions in the system BW, the base        station may send the terminal the frequency domain information        of the CORESET(s) in a method as follows.

Alt 1. The base station may send the terminal the frequency domaininformation of the CORESET(s) using the offset between the centerfrequency of the CORESET(s) and the center frequency of theterminal-received SS block(s).

Alt 2. The base station may send the terminal the frequency domaininformation of the CORESET(s) using the offset between the starting orending point of the CORESET(s) in the frequency domain.

Alt 3. The base station may send the terminal the frequency domaininformation of the CORESET(s) using the position of the CORESET(s) inthe system BW (e.g., starting RB number or RB number associated with thecenter frequency of the CORESET(s)). Here, the position of theCORESET(s) may be the offset value or RB information as described aboveor a value selected among a few candidate values designated in thestandard.

In the case of transmitting the frequency domain information of theCORESET(s) in the scheme of Alt 3, the system BW should be carried inthe MIB.

5) Starting position in time domain (time domain starting point) andperiodicity of the RMSI-related CORESET(s)

-   -   The starting position information (time domain starting point)        of the RMSI-related CORESET(s) may denote the starting time        point of the CORESET(s). For example, this information may be        configured to include the information indicating a subframe (SF)        or a slot from which the CORESET(s) start in a radio frame. The        starting position information may also be configured to include        the information indicating a subframe or an OFDM symbol from        which the CORESET(s) start. The starting position information        may also be configured to include the information on a radio        frame number, a fixed subframe number, or a slot number and an        OFDM symbol number in the subframe or slot from which the        CORESET(s) start. The base station may also transmit information        on a parameter that is not fixed among the radio frame number,        subframe number, and slot number.    -   In the case of configuring the periodicity of the RMSI-related        CORESET(s), the periodicity may be designated as a multiple of        20 ms equal to the default SS periodicity that is assumed by a        user in initial cell access. For example, if the multiple is 2        (or 10 in binary), the periodicity of the RMSI-related        CORESET(s) becomes 40 ms.    -   The starting position and periodicity of the RMSI-related        CORESET(s) may be equal to the starting position of the        periodicity of the RMSI Tx PDSCH. In this case, the starting        position and periodicity information of the RMSI-related        CORESET(s) may not be included in the MIB. The information        indicating that the starting position and periodicity of the        RMSI-related CORESET(s) are equal to the starting position and        periodicity of the RMSI Tx PDSCH may be carried in the MIB.

6) SS burst set periodicity information

-   -   An SS burst set is composed of multiple SS blocks. For example,        it may be possible to aggregate the SS blocks #1 to #M into an        SS burst set in FIG. 1. The SS blocks may be mapped into the SS        burst set contiguously or not. Although a terminal assumes the        SS burst set periodicity of 20 ms in initial access, the network        may configure the periodicity of the SS burst set of the        terminal via UE-specific RRC signaling (UE is the acronym for        user equipment, which corresponds to terminal in the present        disclosure).

7) System beam-related information (information indicating singlebeam-based system or multibeam-based system)

-   -   This information may be a 1-bit indicator included in the MIB or        analogized from the information on the number of SS blocks being        actually transmitted in an SS burst set “actual # of SS blocks        in an SS burst set”. For example, if the number of SS blocks in        an SS burst set is 1, the terminal may assume that the        corresponding system is a single beam-based system; if the        number of SS blocks in an SS burst set is greater than 1, the        terminal may assume that the corresponding system is a        multibeam-based system.

8) Quasi-colocation (QCL) information (e.g., QCL between MIBtransmission beam and DCI transmission beam) (1 bit)

-   -   This information may indicate whether the terminal can assume a        QCL relationship between the PSS/SSS in an SS block or PBCH DMRS        and the PDCCH DMRS carried in the RMSI-related CORESET        corresponding to the SS block. This information is a 1-bit        indicator, and the terminal assumes a non-QCL relationship with        this indicator set to “0” and a QCL relationship with this        indicator set to “1.”

If QCL is configured, this means that the transmission (Tx) beam usedfor a specific SS block is identical with the Tx beam used for a searchspace or a CORESET in specific RMSI-related CORESET(s). Accordingly, thebase station may transmit an indicator indicating whether QCL existsbetween beams or between reference signals and, if QCL is configured,the terminal may notice the beam for the RMSI-related CORESET or searchspace in the CORESET based on the base station Tx beam for the SS block.

If QCL is not configured, this means that the above-describedrelationship is not fulfilled and, in this case, the blind decodingcount of the terminal may increase.

9) Number of mini-slots configured with search spaces within a CORESETor configured with of a CORESET and PDSCH)

-   -   A mini-slot may mean the smallest possible scheduling unit. A        mini-slot may consist of one OFDM symbol and may be configured        to carry at least one of control and data channels.

Here, the information on the number of mini-slots may indicate a numberof search spaces being transmitted on different beams within a CORESETor a number of CORESETs constituting a CORESET group. This informationmay also be configured to indicate a number of mini-slots beingtransmitted on different beams in a PDSCH. This information may beconfigured to indicate a number of mini-slots including search spaceswithin a CORESET or including both the CORESET and PDSCH.

-   -   If the “actual # of SS blocks in an SS burst set” information is        transmitted or QCL is provided between PSS/SSS or PBCH DMRS in        the SS block and the PDCCH DMRS of the CORESET, it may not be        necessary to configure this information in the MIB. This is        because the terminal can notice the beam for transmitting the        RMSI-related CORESET or the search spaces in the CORESET based        on the base station Tx beam carrying the SS block.    -   If a mini-slot denotes a unit including the search spaces in a        CORESET or including both the CORESET and PDSCH, it may not be        necessary to configure the information of 14) to be described        later in the MIB in so far as this information is configured in        the MIB.

10) Number of OFDM symbols in one mini-slot

-   -   If one CORESET is configured for RMSI, this information may be        interpreted as “number of OFDM symbols constituting one search        space within one CORESET.”    -   Or, if multiple CORESETs corresponding to SS block(s) are        configured for RMSI, this information may be interpreted as        “number of OFDM symbols constituting one CORESET.”    -   Or, if a mini-slot includes both the CORESET and PDSCH, this        information may indicate a number of OFDM symbols for        transmitting the CORESET and PDSCH. Accordingly, this        information may indicate a monitoring periodicity of the search        spaces within one CORESET or CORESETs. In this case, it may not        be necessary to configure the information of 14) to be described        later in the MIB.

11) ON/OFF information indicating presence/absence of RMSI-relatedCORESET(s) or PDSCH transmission (1 bit)

-   -   This information indicates presence/absence of an RMSI-related        CORESET or PDSCH transmission and may be replaced by the        RMSI-related CORESET or PDSCH periodicity information (in this        case, if the periodicity-related parameter=0, this may mean the        absence of the RMSI-related CORESET or PDSCH (OFF).

12) System BW

If system BW is configured in the MIB, the RMSI-related PDCCH and PDSCHmay be freely scheduled in the frequency domain within the system BW. Ifthe system BW is not configured in the MIB, the RMSI-related PDCCH andPDSCH transmission may be limited to the minimum carrier BW (or minimumsystem BW), and the transmission frequency position may be fixed.

13) QCL mapping information

-   -   If only one CORESET is configured for RMSI, the QCL mapping        information indicates how many SS blocks are associated with one        search space within the CORESET. For example, if the QCL        relationship is 1:1, this means that the number of search spaces        within a CORESET is equal to the number of SS blocks that are        actually transmitted.    -   If an RMSI-related CORESET group is configured, the QCL mapping        information indicates how many SS blocks are associated with one        core set. For example, if the QCL relationship is 1:1, this        means that the total number of CORESETs is equal to the number        of SS blocks that are actually transmitted.

Meanwhile, the QCL information of 8) and the QCL mapping information of13) may be configured in various manners. For example, if the QCLmapping information is configured, this means that QCL exists; thus, theQCL information may not be configured.

It may also be possible to configure only the QCL information toindicate whether QCL exists by preconfiguring the QCL mappinginformation.

It may also be possible to configure the QCL information and the QCLmapping information with a predetermined number of bits collectively.For example, it may be possible to use 2-bit information, which is setto 00 indicative of no QCL configuration, 01 indicative of the QCLconfiguration with the relationship of 1:1, 10 indicative of the QCLconfiguration with the relationship of 1:2, and 11 indicative of the QCLconfiguration with the relationship of 1:3.

14) CORESET time position information (position information of searchspaces associated with SS blocks in one CORESET or mapping informationof a CORESET associated with SS blocks in one CORESET group)

-   -   The CORESET time position information may indicate the positions        of individual search spaces in the time domain in one CORESET        along with the QCL relationship information.    -   This information may also be configured to indicate how the        CORESETs constituting a CORESET group are mapped in the time        domain along with the QCL relationship information. This        information may indicate the positions of the CORESETs in a slot        carrying the configuration for RMSI-related CORESET        transmission. For example, each CORESET may be mapped to        consecutive or non-consecutive OFDM symbols in a slot.

As aforementioned, the CORESET time position information indicates howthe search spaces of a CORESET or the CORESETs are mapped in the timedomain and may be referred to as CORESET mapping information.

In particular, if the CORESET is mapped to non-consecutive symbols, thisinformation may be used to indicate the position of the CORESET. Forexample, the base station may indicate the starting point of the CORESETvia the aforementioned CORESET starting position information and thenthe OFDM symbol position (time domain) mapped to the CORESET via theCORESET mapping information using bit information. For example, the bitinformation may indicate the number of symbols that are not mapped tothe CORESET or an index of a predetermined CORESET mapping pattern.

Using the above-described CORESET, the base station provides theterminal with RMSI Tx PDSCH scheduling information. The terminal mayidentify information on the CORESET configured in the MIB, and acquirescheduling information for the RMSI Tx PDSCH to which the RMSI is to betransmitted. The information contained in the DCI carried byRMSI-related CORESET(s) may include at least one of following pieces ofinformation, and some of the information may be predefined in thestandard.

1) RMSI payload size

2) MCS

3) Subcarrier spacing

-   -   If the corresponding information is not configured in the MIB,        it may be configured in DCI.

4) Band

-   -   A band may be indicated by a number of PRBs. This information        may be the band information for RMSI Tx PDSCH or band        information for mini-slots including RMSI-related CORESET(s) or        a PDSCH.

5) Frequency position information of RMSI Tx PDSCH

-   -   The frequency position of an RMSI Tx PDSCH may be identical or        not identical with the frequency position of the CORESET        configured in the MIB. The base station may send a terminal        1-bit of information to notify the terminal whether the RMSI Tx        PDSCH frequency position is identical with the CORESET frequency        position.

If the RMSI Tx PDSCH frequency position differs from the CORESETfrequency position, the base station may send the terminal the RMSI TxPDSCH frequency position information. The RMSI Tx PDSCH frequencyposition information is transmitted to the terminal in the same manneras the CORESET frequency position information; thus a detaileddescription of how to transmit the RMSI Tx PDSCH frequency positioninformation is omitted herein.

6) Starting position of RMSI Tx PDSCH in time domain (time domainstarting point) and periodicity

-   -   In the MIB, this information may indicate whether the time        domain position of the RMSI Tx PDSCH is identical with the time        domain position of the CORESET. If the time domain positions        differ from each other, information indicating by how many slots        the RMSI Tx PDSCH position is delayed in comparison with the        slot including the CORESET position is configured in the MIB.

7) SS burst set (SS burst set) periodicity

-   -   If this information is not configured in the MIB, the base        station may send the terminal the SS burst set periodicity        information using DCI.

8) System beam-related information (information indicating singlebeam-based system or multibeam-based system)

-   -   This information may be configured in the form of a 1-bit        indicator in DCI or analogized from the “number of SS blocks        being actually transmitted in an SS burst set (actual # of SS        blocks in an SS burst set).” For example, if the number of SS        blocks being actually transmitted in an SS burst set is 1, the        terminal may assume that the corresponding system is a single        beam-based system; if the number of SS blocks being actually        transmitted in an SS burst set is greater than 1, the terminal        may assume that the corresponding system is a multibeam-based        system.

9) QCL information (e.g., QCL between MIB transmission beam and DCItransmission beam) (1 bit)

-   -   This information may indicate QCL between an MIB or DCI Tx beam        and RMSI Tx beam. The information on the QCL between the MIB or        DCI Tx beam and the RMSI Tx beam may be referred to as        inter-beam QCL. Here, the information on the QCL between the MIB        Tx beam and the DCI Tx beam and the information on the QCL        between the MIB or DCI Tx beam and the RMSI Tx beam may be        referred to as first and second inter-beam QCL information,        respectively.

If QCL is configured between the MIB Tx beam (PBCH DMRS) and RMSI Txbeam (DMRS in RMSI Tx PDSCH), this means that the base station Tx beamfor transmitting a certain SS block is identical with a beam fortransmitting a certain RMSI Tx PDSCH. Accordingly, the base station maytransmit an indicator indicating whether QCL is configured between beamsor between reference signals and, if QCL is configured, the terminal maynotice the beam for transmitting RMSI Tx PDSCH based on the base stationTx beam for transmitting the SS block.

If QCL is not configured, this means that the above-describedrelationship is not fulfilled and, in this case, the blind decodingcount of the terminal may increase.

10) Number of mini-slots (number of mini-slots configured with PDSCH)

-   -   A mini-slot may mean the smallest possible scheduling unit. A        mini-slot may consist of one OFDM symbol and may be configured        to carry at least one of control and data channels.

Here, the information on the number of mini-slots may indicate a numberof mini-slots being transmitted on different beams in a PDSCH. If the“actual # of SS blocks in an SS burst set” information is transmitted orQCL is provided between PSS/SSS or PBCH DMRS in the SS block and theDMRS of RMSI Tx PDSCH, it may not be necessary to configure thisinformation in the DCI. This is because the terminal can notice the beamfor transmitting the RMSI Tx PDSCH based on the base station Tx beam fortransmitting the SS block.

11) Number of OFDM symbols in one mini-slot

-   -   If this information is not configured in the MIB or if it is        designed that the CORESET and PDSCH are transmitted in different        mini-slots, this information may be configured in DCI.

The above-described RMSI-related CORESET or PDSCH Tx mini-slots may beconfigured in various manners, and the information being configured inthe MIB and DCI and RMSI reception (Rx) operation of a terminal varydepending on the configuration of the mini-slot.

As described above, a mini-slot means the smallest possible schedulingunit and may indicate a unit of search space in a CORESET, a unit ofCORESET transmission, a unit of RMSI transmission, or a unit of a searchspace or a CORESET with PDSCH transmission. Detailed descriptionsthereof are made hereinafter.

FIG. 2 is a diagram illustrating a configuration of mini-slots accordingto an embodiment of the present disclosure.

FIG. 2 exemplifies RMSI-related CORESET or PDSCH Tx mini-slots.

In reference to FIG. 2, the RMSI-related CORESET and PDSCH are identicalin periodicity, and the CORESET and PDSCH periodicity information may beconfigured in the MIB. Here, the CORESET and PDSCH may be transmitted inthe same mini-slots, and the mini-slot periodicity may be configured inthe MIB. Here, the periodicity information may mean a monitoringperiodicity information.

A number of mini-slots for transmitting the RMSI-related CORESET andPDSCH (or total number of CORESETs) and a number of OFDM symbols permini-slot may be configured in the MIB. The CORESET may be transmittedin some of the OFDM symbols per mini-slot.

In FIG. 2, the CORESET and PDSCH are frequency division multiplexed(FDMed) in every OFDM symbol of the mini-slots carrying both the CORESETand PDSCH.

FIG. 3 is a diagram illustrating a configuration of mini-slots accordingto another embodiment of the present disclosure.

In the embodiment FIG. 3, the RMSI-related CORESET and PDSCH areidentical in periodicity, and the periodicity information of the CORESETand PDSCH is configured in the MIB. Here, each mini-slot may beconfigured to carry one of the CORESET and PDSCH.

A number of mini-slots for transmitting the RMSI-related CORESET andPDSCH (or total number of CORESETs) and a number of OFDM symbols permini-slot may be configured in the MIB. Here, the CORESET may betransmitted in some of the OFDM symbols constituting a mini-slot. It mayalso be possible to configure the number of OFDM symbols fortransmitting the CORESET per mini-slot in the MIB and the number of OFDMsymbols for transmitting the PDSCH in the DCI.

FIG. 4 is a diagram illustrating a configuration of mini-slots accordingto another embodiment of the present disclosure.

In the embodiment of FIG. 4, the RMSI-related CORESET and PDSCH may notbe identical in periodicity. The CORESET periodicity information may beconfigured in the MIB, and the PDSCH periodicity information may beconfigured in the DCI. In the embodiment of FIG. 4, a mini-slot may bedesigned to carry search spaces constituting a CORESET, a CORESET, or aPDSCH.

A number of mini-slots for transmitting the RMSI-related search spacesor CORESET and PDSCH may be configured in the MIB, or the number ofmini-slots for transmitting the PDSCH may be configured in the DCI. Anumber of OFDM symbols for transmitting the search spaces or CORESET andPDSCH per mini-slot may be configured in the MIB, or only a number ofOFDM symbols corresponding to the search spaces or each CORESET may beconfigured in the MIB while the number of OFDM symbols for transmittingthe PDSCH may be configured in the DCI.

[PDCCH/PDSCH Time Domain Position and Periodicity Configuration]

The RMSI-related CORESET time domain starting position and periodicityinformation may be configured in the MIB, and the RMSI Tx PDSCH timedomain position information may be configured in the MIB or DCI. Inorder to explain the PDCCH/PDSCH Tx time domain position and periodicityinformation configuration, cases for a base station to transmit SS burstsets are depicted in FIGS. 5, 6, and 7.

A terminal may assume the SS burst set transmission periodicitydifferently depending on its operation state (e.g., initial access,CONNECTED, and IDLE state). For example, a terminal attempting initialaccess assumes the SS burst set transmission periodicity of 20 ms.

The base station may configure an SS burst set periodicity that isdifferent from that assumed in the initial access procedure to theterminal in the CONNECTED state (CONN terminal) such that the terminalreceives the SS burst set according to the SS burst set periodicityconfigured by the base station. The base station may set the SS burstset periodicity to one of 5, 10, 20, 40, 80, and 160 ms.

A terminal in the IDLE state (IDLE terminal) may, if necessary, use theSS burst set periodicity configured when it has connected to the networkor attempt to receive the SS burst set according to the SS burst setperiodicity configured for initial access.

FIGS. 5 to 7 show SS burst set transmission schemes in various cases asaforementioned. In the drawings, P_(IA) denotes the default SS burst setperiodicity for initial access, and P_(SS) denotes the SS burst setperiodicity configured by the base station (for CONN and/or IDLE user).P_(Actual) denotes the SS burst set periodicity at which the basestation actually transmits the SS burst set (for CONN and/or IDLE user).

FIG. 5 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure.

As shown in FIG. 5, the base station-configured SS burst set periodicityP_(SS) 510 is equal to the actual SS burst set transmission periodicityP_(Actual) 520 of the base station. The base station-configured SS burstset periodicity P_(SS) 510 may be less than the default SS burst setperiodicity for initial access P_(IA) 530.

In this case, the terminal may receive the SS burst set at a periodicityshorter than the default SS burst set periodicity according to theconfiguration provided by the base station.

FIG. 6 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure.

As shown in FIG. 6, the base station-configured SS burst set periodicityP_(SS) 610 is equal to the actual SS burst set transmission periodicityP_(Actual) 620 of the base station. The base station-configured SS burstset periodicity P_(SS) 610 may be greater than the default SS burst setperiodicity for initial access P_(IA) 630.

In this case, the terminal may receive the SS burst set at a periodicitylonger than the default SS burst set periodicity according to theconfiguration provided by the base station.

FIG. 7 is a diagram illustrating an SS burst set transmission methodaccording to an embodiment of the present disclosure.

As shown in FIG. 7, the default SS burst set periodicity for initialaccess P_(IA) 710 is equal to the actual SS burst set transmissionperiodicity P_(Actual) 720 of the base station. The actual SS burst settransmission periodicity P_(Actual) 720 may be less than the basestation-configured SS burst set periodicity P_(SS) 730.

In this case, the base station may transmit the SS burst set at thedefault SS burst set periodicity for initial access while the terminalmay receive the SS burst set at a periodicity longer than the actual SSburst set transmission periodicity P_(Actual) 720.

Meanwhile, the time domain starting position of the RMSI-relatedCORESET(s) described with reference to FIG. 4 and the CORESET(s) orPDSCH described with reference to FIGS. 2 and 3 may be fixed, and fixingthe time domain starting position may contribute to an information bitsaving effect in the MIB or DCI. That is, if the CORESET or PDSCHstarting time point is fixed, there is no need to configure the startingposition information in the MIB or DCI.

In order to fix the CORESET or PDSCH starting time position, it may bepossible to assume that the CORESET(s) of FIG. 4 or the CORESET(s) orPDSCH of FIGS. 2 and 3 are transmitted in J^(th) slot of +k^(th) framein association with the frame in which the SS burst set carrying thelast PBCH during the last PBCH transmission time interval (TTI) startsbeing transmitted.

In the case where the mini-slots are configured as shown in FIG. 4, thePDSCH transmission position may be fixed in association with theCORESET(s) transmission starting time point. It may also be possible tofix the CORESET(s) transmission starting time point or CORESET(s) orPDSCH transmission staring time position to an absolute time point. Forexample, it may be assumed to start transmission at the J^(th) slot inthe radio frame with a number that makes it possible to obtain an Rvalue when mod is taken with Y.

In the case of fixing the transmission time position of the CORESET(s)or CORESET(s)/PDSCH, the CORESET(s) or reference point of theCORESET(s)/PDSCH recognized by the terminal may be one of the following:

Alt 1. Transmission starting time point of SS burst set carrying lastPBCH in PBCH TTI calculated based on max(P_(SS)) value

Alt 2. Transmission starting time point of SS burst set carrying lastPBCH in PBCH TTI calculated based on P_(IA) value

Alt 3. Transmission starting time point of SS burst set carrying lastPBCH in PBCH TTI calculated based on P_(SS) value (or P_(Actual) value)configured in MIB

Alt 4. Initial access terminal: transmission starting time point of SSburst set carrying last PBCH in PBCH TTI calculated based on P_(IA)value

CONN/IDLE terminal: transmission starting time point of SS burst setcarrying last PBCH in PBCH TTI calculated based on P_(SS) value

In the case of Alt 4, the actual CORESET(s) or CORESET(s)/PDSCHtransmission time point of the base station is calculated based on min(P_(IA), P_(SS)) value.

It may also be possible to fix the CORESET(s) or CORESET(s)/PDSCHtransmission time point to an absolute CORESET(s) transmission positionas well as to fix the CORESET(s) or CORESET(s)/PDSCH transmission timepoint based on the PBCH TTI as in Alt 1 to 4. For example, theRMSI-related CORESET(s) or CORESET(s) or PDSCH) may start beingtransmitted at the U^(th) slot in a frame fulfilling mod (SFN, 5)=0.

Meanwhile, the PBCH TTI may be referenced when configuring theperiodicity of the RMSI-related CORESET(s) of FIG. 4 or theCORESET(s)/PDSCH or PDSCH of FIGS. 2 and 3. For example, it may beassumed that the CORESET(s), CORESET(s)/PDSCH, or PDSCH is transmittedat the position designated as above every L PBCH TTIs. L may beconfigured in the MIB for the case of configuring the periodicity of theRMSI-related CORESET(s) or CORESET(s)/PDSCH or in the DIC for the caseof configuring the periodicity of the RMSI-related PDSCH. The PBCH TTIvalue assumed by the terminal may be one of the following:

Alt 1. PBCH TTI calculated based on max(P_(SS)) value

Alt 2. PBCH TTI calculated based on P_(IA) value

Alt 3. PBCH TTI calculated based on P_(SS) value (or P_(Actual) value)configured in the MIB

The PBCH TTI is a time interval providing the same PBCH contenttransmission and, if it transmits the same PBCH content during the Qconsecutive SS burst sets, the PBCH TTI corresponds to the time intervalof “reference periodicity value (ms)×Q.”

The CORESET(s), CORESET(s)/PDSCH, or PDSCH transmission periodicity maybe set to an absolute periodicity value as well as being configuredbased on the PBCH TTI calculated as one of Alt 1 to 3. For example, itmay be possible to select the RMSI-related CORESET(s), CORESET(s)/PDSCH,or PDSCH periodicity value from {40, 80, 160, 320 ms} defined in thestandard and configure a 2-bit information indicating the selectedvalue.

It may also be possible to reference the default SS periodicity (20 ms)assumed by the terminal in initial access when configuring theRMSI-related CORESET(s) of FIG. 4 or CORESET(s)/PDSCH or PDSCHperiodicity of FIGS. 2 and 3.

[RMSI Application Timing after Receipt of RMSI]

In a multibeam-based system, beam sweeping is performed for completecoverage of a cell in which all terminals can receive a cell-specificsignal, and the MIB and RMSI are representative information broadcast tothe terminal through beam sweeping. Through beam sweeping, the same MIBand RMSI are transmitted on different directional beams. Each terminalmay receive signals on some or all of the sweeping beams. Accordingly,the same RMSI may be received by the terminals at different timings;thus, although the RMSI is received on different directional beams, theRMSI should be applied at the same timing. In particular, because theRMSI is directly scheduled in the CORESET, the terminal may not know theabsolute start time point of the RMSI transmitted through beam sweeping.

The timing for applying the RMSI received by the terminal may bedesignated according to one of the following methods.

Alt 1. Configuring information on a radio frame, subframe, and slot forapplying RMSI in the RMSI

Alt 2. Configuring reference position (radio frame number, subframenumber, slot number, etc.) in the RMSI and applying the RMSI at a radioframe/subframe/slot after offset (+Q) since the default position. Here,the offset value may be transmitted to the terminal in the MIB, RMSI, orDCI or predetermined in the terminal.

Alt 3. Applying the RMSI at the start time point of a radio frame afteran offset, i.e., the +Q^(th) radio frame, based on the radio frame fromwhich transmission of the RMSI-related CORESET starts. Here, the offsetvalue may be transmitted to the terminal in the MIB or DCI orpreconfigured in the terminal.

Alt 4. Applying the RMSI at the start point of a radio frame after anoffset, i.e., the +Qth radio frame, from the radio frame in which theRMSI-related CORESET transmission starts. Here, the offset value (Q) maybe configured in the RMSI.

Alt 5. Apply the RMSI at the transmission time point of a new SS burstset on the basis of the default SS periodicity (20 ms) assumed by theterminal in an initial transmission after an RMSI TTI assumed by theterminal.

Hereinafter, descriptions are made of the aforementioned RMSI schedulinginformation configured in the MIB and DCI and mini-slot design accordingto various embodiments.

One embodiment is directed to the case where mini-slots are configuredas shown in FIG. 2 such that the CORESET(s) and PDSCH periodicity isdetermined based on P_(SS). In this embodiment, the description is madeof a case where there is no need for the terminal to perform blinddecoding on search spaces in the RMSI-related CORESET or CORESET andPDSCH. That is, the description is made of the case where the QCLinformation is set to ON. Here, the QCL information is a 1-bit indicatorset to ON.

This embodiment is directed to a case where a mini-slot configured tosearch spaces or both the CORESET and PDSCH. In this embodiment, a QCLrelationship of 1:1 exists between the PSS/SSS or PBCH DMRS in an SSblock and the PDCCH DMRS in the search spaces/CORESET.

FIG. 8 is a diagram illustrating a resource configuration fortransmitting SS burst sets, RMSI-related CORESETs, and PDSCH accordingto an embodiment of the present disclosure.

In reference to FIG. 8, an SS burst set 810 may consist of 16 SS blocks.Here, it is assumed that the first SS block 811 starts being transmittedat the first OFDM symbol in the frame in which the SS burst settransmission starts. It may transmit the same PBCH content for 4consecutive SS burst sets and that the corresponding position becomesthe frame starting point corresponding to the transmission startingpoint of the fourth SS burst set. However, the present disclosure is notlimited to this embodiment.

The terminal may locate the starting point of the frame carrying the SSburst sets upon receipt of an SS block (based on PBCH or TSS in the SSblock) and, if the standard specifies that the RMSI-related CORESET(s)transmission position is fixed (“fixed value” 840 in FIG. 8), analogizesthe starting point of the RMSI-related CORESET(s) from the startingpoint of the corresponding frame.

If the position of the CORESET is fixed, the starting point of theCORESET may be fixed at an absolute position or determined based on anoffset from the starting point of the frame carrying the SS burst set.If the starting point of the CORESET is fixed, an indicator indicatingthe starting time point of the CORESET may be transmitted to theterminal in the MIB or DCI.

For example, if the starting point of the CORESET is fixed at anabsolute position, the system frame index, subframe index, slot index,and symbol index may be predetermined, or part of the information may betransmitted to the terminal in the MIB or DCI. It may also be possiblethat an offset from the starting point of the frame carrying the SSburst set is preconfigured in the terminal or transmitted to theterminal in the MIB or DCI.

In this case, a parameter indicating the number of SS blocksconstituting an SS burst set may be set to 16 in the MIB, and theterminal may determine that the corresponding system is amultibeam-based system based on this information.

It may be possible that the QCL information or QCL parameter (QCLbetween the PSS/SSS or PBCH DMRS in the SS block and the RMSI-relatedPDCCH DMRS in this embodiment) is set to ON (i.e., Quasi-colocationexists).

It may be possible that a mini-slot is configured to have two OFDMsymbols. In this case, it may be possible to analogize the position of asearch space or CORESET based on the beam on which the terminal hasreceived the SS block (including PBCH). This is because the base stationTx beam for transmitting a specific SS block is identical with the beamfor transmitting the corresponding search space or CORESET in asituation where QCL is configured.

In reference to FIG. 8, if the terminal receives the second SS block 812in the SS burst set, it may receive the DCI in the second CORESET.Because one mini-slot consists of 2 OFDM symbols, the terminal mayreceive the DCI including the RMSI scheduling information transmitted atthe third OFDM symbol 820 counted from the RMSI-related search space ofthe CORESET transmission starting time point (based on the QCLrelationship).

If the network-configured SS burst set periodicity is 40 ms and theRMSI-related CORESET(s)/PDSCH periodicity L is set to 1 under theassumption that the transmission of the same PBCH is provided for 4consecutive SS burst sets in the standard, the transmission periodicitybecomes 160 ms (=40 ms×4×1), as denoted by reference number 830, basedon the RMSI-related CORESET(s)/PDSCH starting point.

However, part of the information may be configured in the DCI. Althoughthe description has been made with specific kinds of information,various other kinds of information may be configured in the MIB and DCI.

FIG. 9 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

In reference to FIG. 9, the terminal may perform synchronization at stepS910. The synchronization may be performed based on the PSS and SSSreceived from a base station.

The terminal may receive the MIB through a PBCH at step S920. Theterminal may obtain the CORESET information from the MIB and receiveRMSI scheduling information (DCI) in the CORESET.

Here, the number of SS blocks constituting the SS burst set may be setto 16 in the MIB and, on the basis of this information, the terminal maydetermine that the corresponding system is a multibeam-based system.

The MIB may include QCL information or a QCL parameter set to ON.

It may be possible that the number of OFDM symbols constituting onemini-slot is set to 2. In this case, the terminal may analogize theposition of a search space or CORESET for receiving signals based on thebeam on which the SS block (including PBCH) is received. The detaileddescription thereof has been described above and thus is omitted herein.

It may be possible that the SS burst set periodicity is set to 40 ms andthe RMSI-related CORESET(s)/PDSCH periodicity L is set to 1 in the MIB.Because the same content can be transmitted for 4 consecutive SS burstsets in the standard, the terminal may assume that the transmissionperiodicity is 160 ms (=40 ms×4×1) based on the RMSI-relatedCORESET(s)/PDSCH starting point.

The MIB may also include the information indicating that a PDCCH orPDSCH position is fixed.

However, part of the above information may be transmitted in the DCI.Although the description is made with specific kinds of information,various other kinds of information may be configured in the MIB and DCI.

At step S930, the terminal may detect the frame boundary based on theinformation contained in the MIB. That is, the terminal may locate aradio frame starting point based on the information carried in the MIB.The terminal may obtain the information on the CORESET position andCORESET periodicity based on the PBCH or TSS.

The terminal may receive the DCI at step S940. In detail, the terminalmay receive the DCI for scheduling RMSI at the identified CORESETposition.

Then, the terminal may receive the RMSI at step S950. That is, theterminal may receive the RMSI in the PDSCH resources identified based onthe DCI.

FIG. 10 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure.

In reference to FIG. 10, the base station may transmit an SS burst setat step S1010. The SS burst set may include the PSS, SSS, TSS, and MIB.

The MIB may also include the information on the CORESET, and the basestation may send the terminal the RMSI scheduling information (DCI) inthe CORESET.

The detailed description of the information being included in the MIBhas been made above with reference to FIG. 9 and thus is omitted herein.

Next, the base station may transmit the DCI at step S1020. In detail,the base station may transmit the DCI including the RMSI schedulinginformation at the designated CORESET position.

Then, the base station may transmit the RMSI at step S1030. The basestation may transmit the RMSI in the PDSCH resources indicated by theRMSI scheduling information.

Various embodiments are directed to the cases where the mini-slots areconfigured as shown in FIG. 2 such that the CORESET(s)/PDSCH periodicityis determined based on P_(SS). These embodiments are directed toinstances where the terminal has to perform blind decoding to receiveRMSI-related PDCCH and PDSCH. That is, the QCL information may not beconfigured or set to OFF in these embodiments. Here, the QCL informationis a 1-bit indicator set to OFF.

These embodiments are directed to cases where a mini-slot is configuredto search spaces or both the CORESET and PDSCH.

In various embodiments, an SS burst set consists of 16 SS blocks asshown in FIG. 8. The terminal may locate the starting point of a framecarrying the SS burst set upon receipt of an SS block (based on the PBCHor TSS in the SS block) and, if the standard specifies that theRMSI-related CORESET(s) transmission position is fixed (“fixed value” inFIG. 10), analogizes the starting point of the RMSI-related CORESET(s)from the starting point of the corresponding frame.

FIG. 11 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

In reference to FIG. 11, the terminal may perform synchronization atstep S1110. The synchronization may be performed based on the PSS andSSS received from the base station.

Next, the terminal may receive the MIB through a PBCH at step S1120. Theterminal may obtain CORESET information from the MIB and receive RMSIscheduling information (DCI) in the corresponding CORESET.

Here, the number of SS blocks constituting the SS burst set may be setto 16 in the MIB and, on the basis of this information, the terminal maydetermine that the corresponding system is a multibeam-based system.

It may be possible that the QCL information or QCL parameter (QCLbetween the PSS/SSS or PBCH DMRS in the SS block and the RMSI-relatedPDCCH DMRS) is set to OFF (i.e., Quasi-colocation does not exist).Accordingly, the terminal cannot analogize the position of a searchspace or CORESET just based on the beam on which the terminal hasreceived the SS block (including PBCH). In this case, it may benecessary to perform blind decoding to decode the DCI from theRMSI-related CORESET(s) starting time point during the CORESET(s)/PDSCHperiodicity at the most. In the case of the single beam-based system, ofcourse, the corresponding DCI is transmitted at the RMSI-relatedCORESET(s) transmission starting time point and thus there is no needfor the terminal to perform blind decoding continuously.

If the network-configured SS burst set periodicity is 40 ms and theRMSI-related CORESET(s)/PDSCH periodicity L is set to 1 under theassumption that the transmission of the same PBCH is provided for 4consecutive SS burst sets in the standard, the transmission periodicitybecomes 160 ms (=40 ms×4×1) based on the RMSI-related CORESET(s)/PDSCHstarting point.

However, part of the information may be configured in the DCI. Althoughthe description has been made with specific kinds of information,various other kinds of information may be configured in the MIB and DCI.

At step S1130, the terminal may detect the frame boundary based on theinformation carried in the MIB. That is, the terminal may locate a radioframe starting point based on the information carried in the MIB. Theterminal may obtain the information on the CORESET position and CORESETperiodicity based on the PBCH or TSS.

The base station may receive the DCI at step S1140. In detail, theterminal may receive the DCI for scheduling the RMSI at the identifiedCORESET position.

On the basis of the DCI, the terminal may obtain the information on thenumber of the OFDM symbols for use in transmitting the RMSI and identifythe PDSCH transmission resources with the exception of the resourcesoccupied by the PDCCH in the band carrying the RMSI-related searchspaces or CORESET and PDSCH within a mini-slot. On the basis of theabove information, the RMSI payload can be transmitted from thecorresponding resource and the code rate according to the RMSI payloadcan also be determined. In this embodiment, the number of OFDM symbolsfor transmitting the RMSI in a mini-slot may be set to 2.

Meanwhile, if the number of SS blocks constituting the SS burst set isset to 1, this means that the corresponding system is a singlebeam-based system and thus the terminal can decode the DCI at theRMSI-related CORESET transmission position without necessity ofperforming a blind decoding.

FIG. 12 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure.

In reference to FIG. 12, the base station may transmit an SS burst setat step S1210. The SS burst set may include the PSS, SSS, TSS, and MIB.

The MIB may include the information on the CORESET, and the base stationmay send the terminal the RMSI scheduling information (DCI) in theCORESET.

The detailed description of the information being included in the MIBhas been made above with reference to FIG. 11 and thus is omittedherein.

Next, the base station may transmit the DCI at step S1220. In detail,the base station may transmit the DCI including the RMSI schedulinginformation at the designated CORESET position. As described above, theDCI may include the information on the number of OFDM symbols for use intransmitting the RMSI.

Finally, the base station may transmit the RMSI at step S1230. The RMSImay be transmitted in the PDSCH resources indicated by the RMSIscheduling information.

FIG. 13 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

In reference to FIG. 13, the terminal may perform synchronization atstep S1310. The synchronization may be performed based on the PSS andSSS received from a base station.

The terminal may receive the MIB through a PBCH at step S1320. Theterminal may obtain the CORESET information from the MIB and receiveRMSI scheduling information (DCI) in the CORESET.

The MIB may not include a parameter indicating the number of SS blocksconstituting the SS burst set and a parameter indicating whether thecorresponding system is a single beam-based system or a multibeam-basedsystem. Accordingly, every terminal has to perform blind decoding todecode the DCI from the CORESET(s) transmission starting position beforethe next period. The MIB may also include no QCL information.

It may be possible that the SS burst set periodicity is set to 40 ms andthe RMSI-related CORESET(s)/PDSCH periodicity L is set to 1 in the MIB.Because the same content can be transmitted for 4 consecutive SS burstsets in the standard, the terminal may assume that the transmissionperiodicity is 160 ms (=40 ms×4×1) based on the RMSI-relatedCORESET(s)/PDSCH starting point.

However, part of the above information may be transmitted in the DCI.Although the description is made with specific kinds of information,various other kinds of information may be configured in the MIB and DCI.

On the basis of the information obtained from the MIB, the terminal maydetect the frame boundary at step S1330. That is, the terminal maylocate a radio frame starting point based on the information carried inthe MIB. The terminal may obtain the information on the CORESET positionand CORESET periodicity based on the PBCH or TSS.

Next, the terminal may receive the DCI at step S1340. In detail, theterminal may receive the DCI for scheduling the RMSI at the identifiedCORESET position.

On the basis of the DCI, the terminal may obtain the information on thenumber of the OFDM symbols for use in transmitting the RMSI and identifythe PDSCH transmission resources with the exception of the resourcesoccupied by search spaces or a CORESET in the band carrying theRMSI-related search spaces or CORESET and PDSCH within a mini-slot. Onthe basis of the above information, the RMSI payload can be transmittedfrom the corresponding resource and the code rate according to the RMSIpayload can also be determined. In this embodiment, the number of OFDMsymbols for transmitting the RMSI in a mini-slot may be set to 2.

FIG. 14 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure.

In reference to FIG. 14, the base station may transmit an SS burst setat step S1410. The SS burst set may include the PSS, SSS, TSS, and MM.

The MIB may include the information on the CORESET, and the base stationmay send the terminal the RMSI scheduling information (DCI) in theCORESET.

The detailed description of the information being included in the MIBhas been made above with reference to FIG. 13 and thus is omittedherein.

Next, the base station may transmit the DCI at step S1420. In detail,the base station may transmit the DCI including the RMSI schedulinginformation at the designated CORESET position. As described above, theDCI may include the information on the number of OFDM symbols for use intransmitting the RMSI.

Finally, the base station may transmit the RMSI at step S1430. The RMSImay be transmitted in the PDSCH resources indicated by the RMSIscheduling information.

An embodiment is directed to the case where the mini-slots areconfigured as shown in FIG. 4 such that the CORESET(s) and PDSCHperiodicities are determined based on P_(SS). The embodiment is directedto a case where there is no need for the terminal to perform blinddecoding to receive RMSI-related CORESET(s) and PDSCH. That is, the QCLinformation is set to ON in this embodiment. Here, the QCL informationis a 1-bit indicator set to OFF.

In this embodiment, it is assumed that a QCL relationship of 1:1 existsbetween the PSS/SSS or PBCH DMRS in the SS block and the PDSCH DMRS.

FIG. 15 is a diagram illustrating a configuration of an SS burst set,RMSI-related CORESET, and PDSCH according to an embodiment of thepresent disclosure.

In reference to FIG. 15, the SS burst set 1510 may consist of 16 SSblocks.

The terminal may locate the starting point of the frame carrying the SSburst sets upon receipt of an SS block (based on PBCH or TSS in the SSblock) and, if the standard specifies that the RMSI-related CORESET(s)transmission position is fixed (“fixed value” 1540 in FIG. 15),analogizes the starting point of the RMSI-related CORESET(s) from thestarting point of the corresponding frame.

If the position of the CORESET is fixed, the starting point of theCORESET may be fixed at an absolute position or determined based on anoffset from the starting point of the frame carrying the SS burst set.If the starting point of the CORESET is fixed, an indicator indicatingthe starting time point of the CORESET may be transmitted to theterminal in the MIB or DCI.

For example, if the starting point of the CORESET is fixed at anabsolute position, the system frame index, subframe index, slot index,and symbol index may be predetermined. It may also be possible that anoffset from the starting point of the frame carrying the SS burst set ispredetermined.

A parameter indicating the number of SS blocks constituting an SS burstset may be set to 16 in the MIB such that the terminal may determinethat the corresponding system is a multibeam-based system based on thisinformation.

It may be possible that the QCL information or QCL parameter (QCLbetween the PSS/SSS PBCH DMRS in the SS block and RMSI-related PDCCHDMRS in this embodiment) is set to ON (i.e., Quasi-colocation exists).

It may also be possible that a mini-slot carrying only one search spaceor CORESET consists of 1 OFDM symbol. The terminal may analogize theposition of the search space or CORESET based on the beam on which theterminal has received the SS block (including PBCH). This is because thebase station Tx beam for transmitting a specific SS block is identicalwith the beam for transmitting the corresponding search space or CORESETin a situation where QCL is configured.

In reference to FIG. 15, if the terminal receives the second SS block1512 in the SS burst set, it may receive the DCI in the second CORESET.Because one mini-slot consists of 1 OFDM symbol, the terminal mayreceive the DCI including the RMSI scheduling information transmitted atthe mini-slot 1520 including the second RMSI-related search space orCORESET counted from the starting time point of the mini-slot carryingthe RMSI-related search space or CORESET (based on the QCLrelationship).

If the network-configured SS burst set periodicity is 40 ms and theRMSI-related CORESET(s) periodicity L_(PDCCH) is set to 1 under theassumption that the transmission of the same PBCH is provided for 4consecutive SS burst sets in the standard, the transmission periodicitybecomes 160 ms (=40 ms×4×1), as denoted by reference number 1530, basedon the RMSI-related CORESET(s)/PDSCH starting point.

By referencing the content of the DCI transmitted in the secondmini-slot 1520, it may be possible that the mini-slot carrying PDSCHconsists of 1 OFDM symbol. However, the above information may beincluded in the MIB.

Because the QCL information or QCL parameter is set to ON in the MIB,the terminal may analogize the position for receiving the PDCCH based onthe beam on which the terminal has received the SS block (or beam onwhich the terminal has received the search space/CORESET).

In reference to FIG. 15, if the terminal has received the second SSblock 1512 in the SS burst set, it may be possible to receive PDSCH inthe second PDSCH mini-slot 1550 counted from the starting time point ofthe RMSI Tx PDSCH mini-slot (based on the QCL relationship).

Here, the RMSI-related PDSCH starting point may be fixed like that ofthe CORESET. In reference to FIG. 15, the RMSI-related PDSCH startingpoint may be set to a fixed value as denoted by reference number 1545such that the terminal may locate the RMSI-related PDSCH starting pointbased on the starting point of the frame carrying the SS burst set. Ifthe PDSCH starting point is fixed, an indicator indicating the fixedPDSCH starting time point may be transmitted to the terminal in the MIBor DCI.

If the position of the PDSCH is fixed, the PDSCH starting point may befixed at an absolute position or determined based on the offset from thestarting point of the frame carrying the SS burst set.

For example, if the PDSCH starting point is fixed at an absoluteposition, the system frame index, subframe index, slot index, and symbolindex may be predetermined, or part of the information may betransmitted to the terminal in the MIB or DCI, as described above. Itmay also be possible that an offset from the starting point of the framecarrying the SS burst set is preconfigured in the terminal ortransmitted to the terminal in the MIB or DCI.

It may also be possible to receive the RMSI Tx PDSCH in the resourcescheduled via the corresponding PDCCH. That is, the information on theresource scheduled via the PDCCH may include the information on theresource for use in transmitting RMSI or data such that the terminal mayreceive the RMSI or data on the PDSCH based on the above information.

If the network-configured SS burst set periodicity is 40 ms and theRMSI-related CORESET(s) periodicity L_(PDCCH) is set to 1 under theassumption that the transmission of the same PBCH is provided for 4consecutive SS burst sets in the standard, the transmission periodicitybecomes 160 ms (=40 ms×4×1) based on the RMSI Tx PDSCH mini-slotstarting point.

However, part of the above information may be transmitted in the DCI.Although the description has been made with specific kinds ofinformation, various other kinds of information may be configured in theMIB and DCI.

FIG. 16 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

In reference to FIG. 16, the terminal may perform synchronization atstep S1610. The synchronization may be performed based on the PSS andSSS received from a base station.

Next, the terminal may receive the MIB through a PBCH at step S1620. Theterminal may obtain the CORESET information from the MIB and receiveRMSI scheduling information (DCI) in the CORESET.

Here, the number of SS blocks constituting the SS burst set may be setto 16 in the MIB and, on the basis of this information, the terminal maydetermine that the corresponding system is a multibeam-based system.

The MIB may include QCL information or a QCL parameter set to ON.

It may be possible that the number of OFDM symbols constituting onemini-slot is set to 1. In this case, the terminal may analogize theposition of a search space or CORESET for receiving signals immediatelybased on the beam on which the SS block (including PBCH) is received.The detailed description thereof has been described above and thus isomitted herein.

It may be possible that the SS burst set periodicity is set to 40 ms andthe RMSI-related CORESET(s)/PDSCH periodicity L is set to 1 in the MIB.Because the same content can be transmitted for 4 consecutive SS burstsets in the standard, the terminal may assume that the transmissionperiodicity is 160 ms (=40 ms×4×1) based on the RMSI-relatedCORESET(s)/PDSCH starting point.

The MIB may also include the information indicating that a PDCCH orPDSCH position is fixed.

At step S1630, the terminal may detect the frame boundary based on theinformation contained in the MIB. That is, the terminal may locate aradio frame starting point based on the information carried in the MIB.The terminal may obtain the information on the CORESET position andCORESET periodicity based on the PBCH or TSS.

The terminal may receive the DCI at step S1640. In detail, the terminalmay receive the DCI for scheduling RMSI at the identified CORESETposition.

The terminal may acquire the information indicating that the mini-slotcarrying the PDSCH consists of 1 OFDM symbol based on the informationcontained in the DCI and analogize the PDSCH position immediately.However, the above information may also be included in the MIB. Thedetailed description thereof has been made above and thus is omittedherein.

The PDSCH position may be fixed as described above.

Next, the terminal may receive the RMSI at step S1650. That is, theterminal may receive the RMSI in the PDSCH resources indicated by theDCI.

FIG. 17 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure.

In reference to FIG. 17, the base station may transmit an SS burst setat step S1710. The SS burst set may include the PSS, SSS, TSS, and MIB.

The MIB may also include the information on CORESETs, and the basestation may send the terminal the RMSI scheduling information (DCI) inthe CORESETs.

The detailed description of the information being included in the MIBhas been made above with reference to FIG. 16 and thus is omittedherein.

Next, the base station may transmit the DCI at step S1720. In detail,the base station may transmit the DCI including the RMSI schedulinginformation at the designated CORESET position.

Then, the base station may transmit the RMSI at step S1730. The basestation may transmit the RMSI in the PDSCH resources indicated by theRMSI scheduling information.

An embodiment is directed to a case where the CORESET(s) and PDSCHperiodicities are determined based on the default SS periodicity (20 ms)assumed by the terminal in an initial access attempt to a cell. In thisembodiment, there is no need for the terminal to perform blind decodingto receive the RMSI-related CORESET(s) and PDSCH. That is, thedescription is made of the case where the QCL information is set to ON.Here, the QCL information is a 1-bit indicator set to ON.

It may also be possible to use QCL mapping information instead of theQCL information and, if the QCL mapping information is configured, theterminal assumes that QCL exists. In this embodiment, there is a QCLrelationship between the PSS/SSS or PBCH DMRS in an SS block and thePDCCH DMRS, and the QCL mapping information is 1:1.

In this embodiment, the search spaces or CORESETs consist of 1 OFDMsymbol each and are transmitted by two, i.e., consecutive search spacesor CORESETs, at an interval of 2 OFDM symbols.

FIG. 18 is a diagram illustrating a resource configuration fortransmitting SS burst sets, RMSI-related CORESETs, and PDSCH accordingto an embodiment of the present disclosure.

In reference to FIG. 18, an SS burst set 1810 may consists of 16 SSblocks.

The terminal may locate the starting point of the frame carrying the SSburst sets upon receipt of an SS block (based on the PBCH or TSS in theSS block) and, if the standard specifies that the RMSI-relatedCORESET(s) transmission position is fixed (“fixed value” 1840 in FIG.18), analogizes the starting point of the RMSI-related CORESET(s) fromthe starting point of the corresponding frame. If the position of theCORESET is fixed, the starting point of the CORESET may be fixed at anabsolute position or determined based on an offset from the startingpoint of the frame carrying the SS burst set.

For example, if the starting point of the CORESET is fixed at anabsolute position, the system frame index, subframe index, slot index,and symbol index may be predetermined, or part of the information may betransmitted to the terminal in the MIB or DCI. It may also be possiblethat an offset from the starting point of the frame carrying the SSburst set is preconfigured in the terminal or transmitted to theterminal in the MIB or DCI.

In this case, a parameter indicating the number of SS blocksconstituting an SS burst set may be set to 16 in the MIB, and theterminal may determine that the corresponding system is amultibeam-based system based on this information.

It may be possible that QCL mapping information (QCL between the PBCHDMRS in the SS block and the PDCCH DMRS in the search space or CORESET)may be configured to indicate 1:1. The QCL mapping information may beset to one of a few values specified in the standard. For example, iffour candidate values of 1:1, 2:1, 6:1, and 8:1 is predesignated, 2-bitQCL mapping information may be configured in the MIB.

The mapping information (time position information) for the CORESETs orsearch spaces in the CORESET that is determined on the basis of theCORESET starting time point may include information indicating how manyconsecutive CORESETs or search spaces are transmitted and informationindicating the interval between consecutive CORESETs or search spaces.

Each CORESET or search space may consist of 1 OFDM symbol, and theterminal may analogize the position of the CORESET or search space forreceiving signals based on the beam on which the terminal has receivedan SS block (including PBCH). This is because the base station Tx beamfor transmitting a specific SS block is identical with the beam fortransmitting the corresponding search space or CORESET in a situationwhere QCL is configured and the QCL mapping relationship is 1:1.

In reference to FIG. 18, if the terminal receives the second SS block1812 in the SS burst set, it may receive the DCI in the second CORESETor service space. Because one mini-slot consists of one OFDM symbol, theterminal may receive the DCI including the RMSI scheduling informationtransmitted in the second CORESET or search space counted from thestarting time point of the RMSI-related CORESET transmission (based onQCL).

Because the SS periodicity assumed by the terminal in initial access is20 ms, if the RMSI-related CORESET(s) periodicity L_(PDCCH) is set to 1,the transmission periodicity becomes 80 ms based on the RMSI-relatedCORESET starting point. The terminal performs RMSI decoding at theresource position scheduled via the RMSI-related CORESET.

However, part of the above information may be transmitted in the DCI.Although the description has been made with specific kinds ofinformation, various other kinds of information may be configured in theMIB and DCI

FIG. 19 is a flowchart illustrating an operation of a terminal accordingto an embodiment of the present disclosure.

In reference to FIG. 19, the terminal may perform synchronization atstep S1910. The synchronization may be performed based on the PSS andSSS received from a base station.

Next, the terminal may receive the MIB through a PBCH at step S1920. Theterminal may obtain the CORESET information from the MIB and receiveRMSI scheduling information (DCI) in the CORESET.

Here, the number of SS blocks constituting the SS burst set may be setto 16 in the MIB and, on the basis of this information, the terminal maydetermine that the corresponding system is a multibeam-based system.

A QCL relationship may be set to 1:1 in the MIB. This information may beprovided with a predetermined number of bits.

The MIB may include time domain mapping information (time positioninformation) of CORESETs or search spaces in the CORESETs that isdetermined on the basis of the CORESET starting time point, and the timeposition information may mean the information indicating the number ofCORESETs or search spaces being consecutively transmitted or theinformation indicating the interval between consecutive CORESETs orsearch spaces.

A mini-slot may consist of 1 OFDM symbol. The terminal may analogize theposition of the search space or CORESET for receiving signals based onthe beam on which the terminal has received an SS block (includingPBCH). The detailed description thereof has been made above and thus isomitted herein.

Because the SS periodicity assumed by the terminal in initial access is20 ms, if the RMSI-related CORESET(s) periodicity L_(PDCCH) is set to 1,the transmission periodicity becomes 80 ms based on the RMSI-relatedCORESET starting point. The terminal performs RMSI decoding at theresource position scheduled via the RMSI-related CORESET.

However, part of the above information may be transmitted in the DCI.Although the description has been made with specific kinds ofinformation, various other kinds of information may be configured in theMIB and DCI

At step S1930, the terminal may detect the frame boundary based on theinformation contained in the MIB. That is, the terminal may locate aradio frame starting point based on the information carried in the MIB.The terminal may obtain the information on the CORESET position andCORESET periodicity based on the PBCH or TSS.

The terminal may receive the DCI at step S1940. In detail, the terminalmay receive the DCI for scheduling RMSI at the identified CORESETposition. The DCI may include the PDSCH resource position andperiodicity for transmitting the RMSI.

Next, the terminal may receive the RMSI at step S1950. That is, theterminal may receive the RMSI in the PDSCH resources identified based onthe DCI.

FIG. 20 is a flowchart illustrating an operation of a base stationaccording to an embodiment of the present disclosure.

In reference to FIG. 20, the base station may transmit an SS burst setat step S2010. The SS burst set may include the PSS, SSS, TSS, and MIB.

The MIB may also include the information on CORESETs, and the basestation may send the terminal the RMSI scheduling information (DCI) inthe CORESETs.

The detailed description of the information being included in the MIBhas been made above with reference to FIG. 19 and thus is omittedherein.

Next, the base station may transmit the DCI at step S2020. In detail,the base station may transmit the DCI including the RMSI schedulinginformation at the designated CORESET position.

Then, the base station may transmit the RMSI at step S2030. The basestation may transmit the RMSI in the PDSCH resources indicated by theRMSI scheduling information.

Hereinafter. a description is made of the DMRS pattern configurationmethod according to an embodiment of the present disclosure.

Before a terminal camps on a cell (RRC CONN), the base station mayconfigure a default DMRS pattern via the MIB, RMSI, or MIB and RMSI.This pattern may be configured per physical channel, such as physicalchannels including uplink and downlink physical channels between a basestation and a terminal. It may also be possible to configure differentpatterns in downlink (DL) and uplink (UL) channels.

For example, the base station may configure a default DMRS pattern tothe terminal per service or deployment scenario. For example, it may bepossible to configure a DMRS pattern dense in view of time density tothe terminal for a cell deployed near an expressway. Before establishinga connection to the base station (entering RRC CONN state), the terminalattempts data decoding on a DL channel or transmits data on a UL channelaccording to the default pattern configured by the base station.

After entering the connected state (RRC CON), the terminal may update,if necessary, the DMRS pattern through UE-specific RRC signaling. It mayalso be possible to configure a set of DMRS patterns through RRCsignaling and, if necessary, transmit a value of the DMRS patternselected from the DMRS pattern set via the DCI or medium accesscontrol-control element (MAC-CE) to configure the selected DMRS pattern.

The UE-specific DMRS pattern configuration may be performed viaUE-specific RRC signaling or DCI in a terminal feedback-based manner.For example, terminals may perform channel measurement and transmitfeedback information such as frequency-selectivity characteristics andDoppler characteristics of the channel, and the base station may assigna DMRS pattern with a high frequency domain density to the terminal witha high frequency selectivity and a DMRS pattern with a high time domaindensity to the terminal with a high Doppler characteristic. In a hybridautomatic repeat request (HARD) process, the base station may select aDMRS pattern with a high frequency domain and/or time domain densityfrom the DMRS pattern set and assign the selected DMRS pattern to theterminal according to the number of retransmissions. It may also bepossible for the terminal to change the DMRS pattern for a new one witha high frequency or time domain density for UL transmission autonomouslyaccording to the number of retransmissions.

Hereinafter, a description is made of the reference signal designmethod. FIG. 21 is a diagram illustrating a configuration of mini-slotsconsisting of 2 OFDM symbols each.

In reference to FIG. 21, a mini-slot may consist of OFDM symbol #1 andOFDM symbol #2. In this case, it may be possible to transmit and receivedata on two different directional beams per mini-slot. It may also bepossible to use the same directional beam for the OFDM symbols of thesame mini-slot.

FIGS. 22 and 23 are diagrams for explaining a reference signal designmethod according to an embodiment of the present disclosure.

FIGS. 22 and 23 show reference signal (RS) designs for the case where anRMSI-related PDCCH, RMSI-related PDCCH/PDSCH, or RMSI Tx PDSCH istransmitted in two consecutive OFDM symbols (same beam is used in theOFDM symbols constituting a mini-slot). FIGS. 22 and 23 show the samereference signal design method and show how to design the referencesignal in the frequency and time domains.

In the case that a mini-slot is transmitted on a beam, it may bepossible to design and map orthogonal cover code (OCC) patterns for OCCprocessing in the frequency and time domains as shown in FIGS. 22 and23.

That is, the OCC corresponding to the second antenna port is applieddifferently depending on whether the OFDM symbol position is an evenindex OFDM symbol position or an odd index OFDM symbol position. Adescription is made of the OCC mapping with reference to FIG. 24.

FIG. 24 is a diagram illustrating a table with OCC mapping per antennaport.

In reference to FIG. 24, the OCC mapping is performed differentlyaccording to the odd index OFDM symbol, even index OFDM symbol, andantenna port. Although various mappings are shown in FIG. 24, themappings may be changed in various manners without breaking theorthogonality.

In FIGS. 22 and 23, each smallest square block denotes an RE, thevertical axis denotes subcarriers, and the horizontal axis denotes OFDMsymbols. The shaded REs are REs to which a reference signal is mapped.

The frequency domain length 2-OCC processing may be performed as shownin FIG. 22. In FIG. 22, four subcarriers are used for reference signaltransmission.

In this case, the length 2-OCC processing is performed by the twosubcarriers such that it is possible to process the reference signalswith at least two length 2-OCCs and up to three length 2-OCCs.

In the case of using two length 2-OCCs, the reference signals on thefirst and second reference signal subcarriers from the top are processedwith one length 2-OCC 2210, and the reference signals on the third andfourth reference signal subcarriers from the top are processed with theother length 2-OCC 2220. In the case of using three length 2-OCCs, thereference signals on the second and third reference signal subcarriersare processed with an additional length 2-OCC 2230.

In the case of the time domain length 2-OCC processing of FIG. 23, itmay be possible to apply the length 2-OCCs to the reference signalsmapped to the two consecutive OFDM symbols on the reference signalsubcarriers. In reference to FIG. 23. OCC=[+1 +1] is applied to thefirst RE pair for Ant. Port 0 as denoted by reference number 2310, andOCC=[+1 −1] is applied to the first RE pair for Ant. Port 1 as denotedby reference number 2320. Likewise, OCC=[+1 +1] is applied to the secondRE pair for Ant. Port 0 as denoted by reference number 2330, and OCC=[+1−1] is applied to the second RE pair for Ant. Port 1 as denoted byreference number 2340. In the two-port space frequency block code-based(SFBC-based) beam sweeping broadcast according to a representativeembodiment of the present disclosure, the channel estimation on twoantenna ports may be performed as described above. The signal receptionalgorithm may be designed to perform channel estimation by taking intoconsideration the frequency domain and time domain processing aspectsselectively or in combination. The present disclosure is not limited tothe RMSI-related PDCCH and/or PDSCH transmission, and it may beapplicable to any type of signal transmission that allows forapplication of a time/frequency domain OCC to all the types of physical(PHY) channels for transmitting information in two or more consecutiveOFDM symbols using a beam directly or in an extended or modified manner.The OCC values may be changed if the change does not break the mutualorthogonality. It may be possible to increase the length of the OCC asthe number of OFDM symbols for transmitting a signal on the same beamincreases.

As described above, in the case of transmitting data or controlinformation in the same beam direction for a predetermined number ofOFDM symbols, it may possible to apply an OCC to the RSs for channelestimation on a plurality of antenna ports in the corresponding area.The terminal may perform channel estimation using the RS transmitted atpredetermined OFDM symbols in the same beam direction.

Although not described, it may be possible to design a trackingreference signal (TRS) being configured in the MIB for transmitting theRMSI-related PDCCH and/or PDSCH and use the TRS instead of anyindependent reference signal. The TRS may be a reference signal formeasuring a time/frequency offset continuously, a reference signal forbeam management (e.g. base station Tx beam/terminal Rx beam pairdetermination), a reference signal for L3 mobility, or a referencesignal for any combination of the aforementioned functionalities.

FIG. 25 is a diagram illustrating a design of TRSfrequency-division-multiplexed (FDMed) with RMSI-related PDCCH or PDSCHfor TRS-based channel estimation according to an embodiment of thepresent disclosure.

A description is made of the method for designing a TRS FDMed with abeam reference signal (BRS) and RMSI-related PDCCH or PDSCH in an OFDMsymbol for use of the TRS in RMSI-related PDSCH or PDSCH channelestimation with reference to FIG. 25.

In FIG. 25, a square block denotes an RE, and the TRS and RMSI-relatedPDCCH and/or PDSCH are FDMed by the 12 subcarriers. FIG. 25 is depictedunder the assumption that the number of antenna ports is 8, but thepresent disclosure is not limited to this embodiment.

As shown in FIG. 25, the present disclosure proposes a TRS design methodof binding TRSs being transmitted through 8 antenna ports in pairs andapplying length-2 OCCs to each pair for separating the TRSs. In the2-port SFBC-based beaming sweeping broadcast, per-port channelestimations may be accomplished by performing OCC decoding by the twosubcarriers.

In a case of the 2-port SFBC for transmitting the RMSI-PDCCH or PDSCHthrough one port or beam formed with Ant. Ports #0, #2, #4, and #6 andthe other port or beam formed with Ant. Port #1, #3, #5, and #7, aterminal may perform TRS-based per-port channel estimation and estimatechannels for the two ports of the RMSI-related PDCCH and/or PDSCH basedon the TRS-based per-port channel estimation result.

FIG. 26 is a diagram illustrating a design of a BRS for channelestimation based on a TRS FDMed with the RMSI-related PDCCH or PDSCHaccording to a number of antenna ports.

FIG. 26 exemplifies TRS transmission for a case where the number of TRStransmission antenna ports is less than 8, i.e., 2 or 4.

In a situation where a terminal does not know the number of antennaports for TRS transmission before decoding the RMSI-related PDCCH orPDSCH and thus has to perform blind decoding, the terminal can estimatea channel value corresponding to an antenna port for RMSI-related PDCCHor PDSCH based on the channel values by the two subcarriers to which oneOCC has been applied and then the other channel value corresponding tothe other antenna port for RMSI-related PDCCH or PDSCH based on thechannel values by the two subcarriers to which the other OCC has beenapplied.

The designs of FIGS. 25 and 26 may be applied to a case where amini-slot consists of one or more OFDM symbols.

A description is made of the method for designing a TRS timedivision-multiplexed (TDMed) with RMSI-related PDCCH and/or PDSCH in thecase where a mini-slot consists of two OFDM symbols with reference toFIG. 27.

FIG. 27 is a diagram illustrating a design of a TRS TDMed withRMSI-related PDCCH or PDSCH for TRS-based channel estimation accordingto an embodiment of the present disclosure.

The TRS may be designed in the same manner as described with referenceto FIG. 25 or 26. Assuming that there is little channel variation andthe same beam is applied during a predetermined number of consecutiveOFDM symbols, it is possible to use the TRS-based channel estimationresult to decode RMSI-related PDCCH or PDSCH decoding.

The present disclosure is not limited to the RMSI-related PDCCH and/orPDSCH transmission, and it may be applicable to any type of channelestimation with signals separated by OCC using the characteristic oftransmitting FDMed or TDMed reference signals and channel on the samedirectional beam. The OCC values may be changed if the change does notbreak the mutual orthogonality. It may be possible to increase thelength of the OCC as the number of OFDM symbols for transmitting asignal on the same beam increases. It may also be possible to increasethe OCC length according to the mapping the reference signals onsubcarriers in a symbol and a broadcast channel.

Although the descriptions are directed to reference signal designs, fora case where the RMSI-related PDCCH or PDSCH is transmitted in 2-portdiversity mode (i.e., 2 port SFBC), to differentiate two ports with OCCin each frequency resource and estimate per-port channels of theRMSI-related PDCCH or PDSCH based on the channel values estimated withthe same OCC in each frequency resource, the present disclosure mayinclude embodiments in which the RMSI-related PDCCH or PDSCH istransmitted in 4-port diversity mode (i.e., 4 port SFBC) todifferentiate four antenna ports with OCC in each frequency resource andestimate per-port channels of the RMSI-related PDCCH or PDSCH based onthe channel values estimated with the same OCC in each frequencyresource.

FIG. 28 is a block diagram illustrating a configuration of a terminalaccording to an embodiment of the present disclosure.

As shown in FIG. 28, the terminal may include a transceiver 2810, acontroller 2820, and a memory 2830. In the present disclosure, thecontroller may be a circuit, an application-specific integrated circuit,or at least one processor. The processor may be controlled by a programincluding instructions for executing a method according to an embodimentof the present disclosure. The program may be stored in a storagemedium, and examples of the storage medium include volatile andnon-volatile memories. The memories may be media that are capable ofdata and, if configured to store the instructions, may not be limited intype.

The transceiver 2810 may transmit and receive signals to and from othernetwork entities. For example, the transceiver 2810 may receive systeminformation, synchronization signals, and reference signals from a basestation.

The controller 2820 may control overall operations of the terminal asproposed in the present disclosure. In detail, the controller 2820 maycontrol the operations for receiving RMSI in a multibeam-based system asproposed in the present disclosure.

The memory 2830 may store at least one type of information beingtransmitted and received by the transceiver 2810 and generated by thecontroller 2820. For example, the memory 2830 may store RMSItransmission-related scheduling information and RMSI-related PDCCH timedomain position and periodicity information.

FIG. 29 is a block diagram illustrating a configuration of a basestation according to an embodiment of the present disclosure.

As shown in FIG. 29, the base station may include a transceiver 2910, acontroller 2920, and a memory 2930. In the present disclosure, thecontroller may be a circuit, an application-specific integrated circuit,or at least one processor. The processor may be controlled by a programincluding instructions for executing a method according to an embodimentof the present disclosure. The program may be stored in a storagemedium, and examples of the storage medium include volatile andnon-volatile memories. The memories may be media that are capable ofstoring data and, if configured to store the instructions, may not belimited in type.

The transceiver 2910 may transmit and receive signals to and from othernetwork entities. For example, the transceiver 2910 may transmit systeminformation, synchronization signals, and reference signals to a basestation.

The controller 2920 may control overall operations of the base stationproposed in the present disclosure. In detail, the controller 2920 maycontrol the operations for transmitting RMSI in the multibeam-basedsystem as proposed in the present disclosure.

The memory 2930 may store at least one type of information beingtransmitted and received by the transceiver 2910 and generated by thecontroller 2920. For example, the memory 2930 may store RMSItransmission-related scheduling information and RMSI-related PDCCH timedomain position and periodicity information.

As described above, the present disclosure is advantageous in terms ofmaking it possible for a terminal to acquire RMSI securely bytransmitting RMSI transmission scheduling information via the MIB andDCI.

The embodiments disclosed in the specification and drawings are proposedto help explain and understand the present disclosure rather than tolimit the scope of the present disclosure. It is therefore intended thatthe following claims be interpreted to include all alterations andmodification made to the disclosed embodiments as fall within the spritand scope of the disclosure.

Meanwhile, in the drawings illustrating a method in embodiments, theorder of description does not necessarily correspond to the order ofexecution, and the order relationship may be changed or executed inparallel.

Alternatively, the drawings illustrating the method of the disclosuremay omit some of the elements and may include only some of the elementswithout impairing the essence of the disclosure.

Further, the method of the disclosure may be carried out in combinationwith some or all of the contents included in each embodiment withoutdeparting from the essence of the disclosure.

Although the present disclosure has been described with variousembodiments, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed is:
 1. A method performed by a terminal in a wirelesscommunication system, the method comprising: receiving, from a basestation, a master information block (MIB); identifying, based on theMIB, information on a control resource set (CORESET) on which controlinformation for system information is received, the information on theCORESET including information indicating a starting symbol index of theCORESET; receiving the control information based on the CORESET; andreceiving, from the base station, the system information based on thecontrol information, wherein the information on the CORESET furtherincludes information indicating a number of resource blocks of theCORESET a number of symbols of the CORESET, and offset information froma starting resource block of the CORESET to a frequency associated witha synchronization signal block.
 2. The method of claim 1, wherein theMIB further includes information on a subcarrier spacing for theCORESET.
 3. The method of claim 1, wherein the information on theCORESET includes quasi-colocation (QCL) information, and whereinidentifying the control information comprises identifying, in case thatthe QCL information is configured, the control information in theCORESET corresponding to a transmission beam on which the MIB istransmitted.
 4. A method of a base station in a wireless communicationsystem, the method comprising: transmitting a master information block(MIB) including information on a control resource set (CORESET) on whichcontrol information for system information is transmitted, theinformation on CORESET including information indicating a startingsymbol index of the CORESET; transmitting the control information basedon the CORESET; and transmitting the system information based on thecontrol information, wherein the information on the CORESET furtherincludes information indicating a number of resource blocks of theCORESET a number of symbols of the CORESET, and offset information froma starting resource block of the CORESET to a frequency associated witha synchronization signal block.
 5. The method of claim 4, wherein theMIB further includes information on a subcarrier spacing for theCORESET.
 6. The method of claim 4, wherein the information on theCORESET includes quasi-colocation (QCL) information, and whereintransmitting the control information comprises transmitting, in casethat the QCL information is configured, the control information in theCORESET corresponding to a transmission beam on which the MIB istransmitted.
 7. A terminal in a wireless communication system, theterminal comprising: a transceiver; and a controller configured to:receive, via the transceiver from a base station, a master informationblock (MIB), identify, based on the MIB, information on a controlresource set (CORESET) on which control information for systeminformation is received, the information on the CORESET includinginformation indicating a starting symbol index of the CORESET, receive,via the transceiver from the base station, the control information basedon the CORESET, and receive, via the transceiver from the base station,the system information based on the control information, wherein theinformation on the CORESET further includes information indicating anumber of resource blocks of the CORESET a number of symbols of theCORESET, and offset information from a starting resource block of theCORESET to a frequency associated with a synchronization signal block.8. The terminal of claim 7, wherein the MIB further includes informationon a subcarrier spacing for the CORESET.
 9. The terminal of claim 7,wherein the information on the CORESET includes quasi-colocation (QCL)information, and wherein the controller is configured to identify, incase that the QCL information is configured, the control information inthe CORESET corresponding to a transmission beam on which the MIB istransmitted.
 10. A base station in a wireless communication system, thebase station comprising: a transceiver; and a controller configured to:transmit, via the transceiver, a master information block (MIB)including information on a control resource set (CORESET) on whichcontrol information for system information is transmitted, theinformation on the CORESET including information indicating a startingsymbol index of the CORESET, transmit, via the transceiver, the controlinformation based on the CORESET, and transmit, via the transceiver, thesystem information based on the control information, wherein theinformation on the CORESET further includes information indicating anumber of resource blocks of the CORESET a number of symbols of theCORESET, and offset information from a starting resource block of theCORESET to a frequency associated with a synchronization signal block.11. The base station of claim 10, wherein the MIB further includesinformation on a subcarrier spacing for the CORESET.
 12. The basestation of claim 10, wherein the information on the CORESET includesquasi-colocation (QCL) information, and wherein the controller isconfigured to transmit, in case that the QCL information is configured,the control information in the CORESET corresponding to a transmissionbeam on which the MIB is transmitted.